Embodiments disclosed herein generally relate to lighting systems. More specifically, embodiments disclosed herein relate to an improved system and method for distributing power and data signals in a lighting system.
Display units for entertainment, architectural, and advertising purposes have commonly been constructed from numbers of light emitting elements, such as light emitting diodes (LEDs) or incandescent lamps. The light emitting elements may be selectively turned on and off to create patterns, graphics, and video displays for both informational and aesthetic purposes. It is well known to construct tubular lighting and display devices using LEDs and various methods have been used for distributing data and power signals through such devices.
U.S. Pat. No. 6,472,823, issued to George Yen, uses a daisy-chain system where control and power enters one end of a tube fixture, is carried through the tube, and leaves the other end to connect to the next fixture. The power supply is at one end of the chain so that the system may be limited by the number of tubes that are connected in the chain by the capacity of that power supply. U.S. Pat. No. 6,857,924, issued to Ta-Hao Fu, and U.S. Pat. No. 6,860,007, issued to Li-wen Liu, are also similarly used.
U.S. Pat. No. 7,053,557, issued to Robert Cross, describes supplying power in parallel to multiple LED tube fixtures but does not disclose doing so in a way that allows multiple power supplies to be used or means to economically distribute and protect the cabling systems. In addition the low voltage power supplies are contained within the tube where heat management could be problematic.
U.S. Pat. No. 7,067,992, issued to Susan Leong, describes another method for connecting power to an LED tube fixture but does not explain how data signals may also be connected.
U.S. Pat. No. 6,676,284, issued to Wynne Willson, describes an LED tube fixture system with multiple power supplies and a data signal path but does not teach means for connecting the power supplies and routing the cables to minimize fixture size.
LED tube fixtures of this type are often used in architectural situations where it is a requirement to maintain a clean and tidy appearance for the fixture with hidden cabling and seamless joins between fixtures. Another requirement is that the power supplies are mounted in such a way that access for installation and maintenance is simple. Finally, it would be advantageous to provide protection for power and data cabling without the need to run separate cable conduits or trunking adjacent to the fixtures.
This invention seeks to provide means for distributing power and data signals in an LED lighting or display fixture that may minimize the size of the fixture and eliminate the need to run alternating current (AC) power in a separate cable alongside the fixture.